A 4 inch by 17 inch PIAT round. Painted brown indicating a low explosive charge meant to injure the armoured unit’s driver but allow the vehicle to be captured by friendly units.

The Projector, Infantry, Anti Tank (PIAT) Mk I was a British man-portable anti-tank weapon developed during the Second World War. The PIAT was designed in 1942 in response to the British Army’s need for a more effective infantry anti-tank weapon and entered service in 1943.

The PIAT was based on the spigot mortar system, and projected (launched) a 2.5 pound (1.1 kg) shaped charge bomb using a cartridge in the tail of the projectile. It possessed an effective range of approximately 115 yards (105 m) in a direct fire anti-tank role, and 350 yards (320 m) in an indirect fire role. The PIAT had several advantages over other infantry anti-tank weapons of the period: it had greatly increased penetration power over the previous anti-tank rifles, it had no back-blast which might reveal the position of the user or accidentally injure friendly soldiers around the user, and it was simple in construction. However, the device also had some disadvantages: powerful recoil, a difficulty in cocking the weapon, and early problems with ammunition reliability. The projectile also had to hit the target at right angles. If not it had a tendency to bounce off the target vehicle.

The PIAT was first used during the Tunisia Campaign in 1943, and remained in use with British and other Commonwealth forces until the early 1950s. PIATs were supplied to or obtained by other nations and forces, including the Soviet Union (through Lend Lease), the French resistance, the Polish Underground, and the Israeli Haganah (which used PIATs during the 1948 Arab–Israeli War). Six members of the British and other Commonwealth armed forces received Victoria Crosses for their use of the PIAT in combat.